DuMont was an American scientist, inventor and broadcaster best known for improvements to the cathode ray tube for use in television receivers (beginning in 1931), and later as the founder of the DuMont television network. In 1938, his company manufactured the DuMont Model 180 television receivers, the first all-electronic television sets ever sold to the public in the U.S.A. This was a few months prior to RCA's first TVset on the market, the TRK-12. DuMont later went on to found in 1946 the first television network to be licensed, the DuMont Television Network, initially by linking station WABD (named for DuMont) in New York City to station WTTG in Washington, DC. (WTTG was named for Dr. Thomas T. Goldsmith, DuMont's Vice President of Research, and his best friend).

DuMont was born in Brooklyn, New York. At the age of 10, he was stricken with polio and was quarantined at his family's Eastern Parkway apartment for nearly a year. During his quarantine, his father brought home books and magazines for the young DuMont to read while bedridden. At this time, DuMont developed an interest in science, specifically wireless radio communication, and taught himself Morse code. His father bought him a crystal radio receiver which he assembled, took apart, reassembled and rebuilt several times. He improved his set each time he rebuilt it and later built a transmitter, while his father obtained the landlord's permission to erect a 30-foot high transceiving antenna on the roof.

While recuperating from polio, DuMont was advised to swim to regain the use of his legs. In 1914, the family moved to Montclair, New Jersey, where there was an indoor year-round pool available at the local YMCA. He graduated from Montclair High School in 1919, and went to Rensselaer Polytechnic Institute in Troy, NY.

In 1915, DuMont became the youngest American to obtain a first class commercial radio operator's license at age 14. The following summer, he worked as a radio operator aboard a coastal steamer making runs from New York to Providence, Rhode Island. As the summers went by, he made his way to the Caribbean, South America and, after World War I, to Europe, where, during the summer of 1922, he was stuck in Copenhagen for months because of a dock workers strike.

After graduating from Rensselaer in 1924, DuMont worked at the Westinghouse Lamp Company in Bloomfield, New Jersey, in charge of radio tube production. While there, he increased production from 500 tubes per day to an astounding 50,000 tubes per day. Management decided to give him a $500 bonus, a small raise, and the "Westinghouse Award", an award devised to recognize his accomplishments. The "Westinghouse Award" was later presented as a scholarship award to high school seniors showing promise in a field of science.

By 1928, DuMont was searching for new opportunities and was wooed by Dr. Lee De Forest, a radio pioneer who developed the audion tube, the original voice amplifier for radio reception. De Forest had a checkered career as an inventor and had several failed business ventures. DuMont was hired as vice president and production manager for radio tubes. Here he came in contact with a mechanical television, one that De Forest had purchased from C. Francis Jenkins. DuMont worked to improve television transmission and reception and went to De Forest asking for funds to build a long lasting cathode ray tube for television reception. De Forest denied DuMont's request as De Forest's investors were demanding better returns. Subsequently, DuMont resigned at the same time that De Forest sold his radio manufacturing business to David Sarnoff at RCA.

DuMont then started his own company, DuMont Laboratories, in the basement of his Cedar Grove, New Jersey home, building long-lasting cathode ray tubes. In 1931, he sold two tubes to two college science laboratories for $35 each.

In 1932, DuMont proposed a "ship finder" device to the US Signal Corps at Fort Monmouth, New Jersey, that used radio wave distortions to locate objects on a cathode ray tube screen. The US military asked him not to take out a patent for developing what they wanted to maintain as a secret, and so he is not often mentioned among those responsible for early "radar" using a cathode ray tube. It was not called radar back then, the US Army's Signal Corps called it "radio position finding (RPF)". The term "radar", an acronym for "Radio Detection And Ranging", was invented in 1940 by US Navy researchers and wasn't adopted by the British until 1943. DuMont did, however, go on to develop long-range precision radar to aid the Allies during WWII. As a consequence the French Government knighted him in 1952.

During the early years of World War II, DuMont received special government contracts to provide large 36" wide cathode ray tubes. These special very large tubes allowed scientists working on the Manhattan Project to study the action of accelerated electrons.

DuMont produced black and white televisions in the 1940s and 1950s that were generally regarded as offering highest quality and durability. Many of these premium sets included a built in AM/FM radio and record player.

The DuMont Television Network was not an unqualified success, being faced with the major problem of how to make a profit without the benefit of an already established radio network as a base. After ten years, DuMont shuttered the network and sold what remained of his television operations to John Kluge in 1956, which Kluge renamed Metromedia.

DuMont sold his manufacturing operations in 1960. The television manufacturing division was sold to Emerson Radio. His research laboratory became part of Fairchild Camera and later developed semiconductor microchips. Robert Noyce, founder of Intel, originally worked for DuMont as an engineer. In the early 1960s, the Dumont laboratory, now owned by Fairchild, developed the original Sony Trinitron color picture tube, under a subcontract.

DuMont was the first to provide funding for educational television broadcasting. He was the recipient of numerous honorary degrees and awards, among them the Cross of Knight awarded by the French Government, the Horatio Alger Award, the Westinghouse Award, and the DeForest Medal.

DuMont died in 1965 and is buried in Mount Hebron Cemetery in Upper Montclair, New Jersey. The television center at Montclair State University bears his name.